AAV for sewage pump

We are finishing out a basement below a double wide that has a roughed-in bath (not our rough-in). There was no allowance for venting any of the bath fixtures, wasn't even a trap run under tub drain rough-in. Is there an AAV available that would vent the sewage pump? Would have to do major destruction upstairs to make access for roof venting. Dug out enough sand to get the tub trap in but am at at a stand-still till venting issue is fixed. Help! Tks, justin

Well now hang on a minute. god I'm gonna hate myself for this but..... according to the 09 IPC you can indeed vent an ejector tank provided the system is engineered. So..... if you go to Studor's web site and do some fishing around you will find an engineered schematic for venting an ejector tank using an aav. What a world...... what a world....

A sewage ejector system is a "closed system", so HOW can a Studor/AAV which can only allow air IN, be expected to exhaust air that had to be displaced by the incoming water? The Studor sites says, "It can be used on ejectors, IF done in an engineered, (meaning designed and certified by a professional mechanical engineer), manner, AND approved by local codes, BUT does NOT tell how it can be done> In fact EVERY specification sheet says that there MUST be at least ONE relief vent on the system. It is possible that they mean that an AAV can be installed ON the ejector pit, IF the fixtures themselves have an atmospheric vent, which would work.

Doing it that way means you do NOT even need the AAV. And it also means that if the main line is plugged up, the sewage will flow down the vent into the ejector basin where it will promply flood the area.

Again, and sadly, an inspector can't do much about it other than scratch his head. I actually took this issue to both the Maine and NH plumbing boards and though we were all in agreement over the stupidity of the whole thing, unless someone passes an amendment, there's nothing that can be done about it.